JPH0611607A - Production of diffraction grating - Google Patents

Abstract

PURPOSE:To produce a diffraction grating capable of diffracting the light in the wide range of wavelength by laminating >=2 kinds of polymer layers having a different refractive index so that the thicknesses of the layers are varied. CONSTITUTION:High-refractive-index polymer layers 1, 3 and 5 and low- refractive-index polymer layers 2, 4 and 6 are alternately laminated by coating to form a layer consisting of >=2 kinds of polymers having a different refractive index. The wavelength of the diffracted light is controlled to 800-2000nm by varying the thicknesses of the layers, and a heat reflecting film transmitting visible light and reflecting heat rays is obtained in this case. The laminate is applicable to a color filter for reflecting a light of specified wavelength in the visible region, a UV cutoff film, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a diffraction grating, and more particularly, to a method for manufacturing a diffraction grating that diffracts a wide wavelength range such as a heat ray reflective film.

[0002]

2. Description of the Related Art As a conventional diffraction grating, a Bragg diffraction grating formed by recording light interference fringes on a film of photopolymer, dichromated gelatin, silver salt or the like is well known.
However, all of these have a narrow range of diffraction wavelengths, and no one capable of diffracting a wide wavelength range has been obtained.

In order to use such a Bragg diffraction grating for applications such as a heat ray reflective film, it is necessary for the diffraction wavelength to be in the range of several hundred nm or more.

[0004]

The present invention has been made in view of such a situation, and an object thereof is to make two or more kinds of polymer layers having a difference in refractive index different in thickness between some layers. It is to provide a method of manufacturing a Bragg diffraction grating capable of diffracting a wide wavelength range by stacking the layers on the Bragg diffraction grating.

[0005]

In the method of manufacturing a diffraction grating of the present invention for solving the above problems, there is provided a method of manufacturing a polymer layer having a difference in refractive index, which is laminated with at least some layers having different thicknesses. In the above, the spin coating method is used as the coating means, and the film thickness is controlled by changing the viscosity of the coating solution and the rotation speed of the spin coating.
Therefore, the diffraction efficiency and the diffraction wavelength can be arbitrarily set by changing the film thickness of the polymer film, the number of laminated layers, and the difference in the refractive index. This is a very simple and wide-ranging diffraction grating manufacturing method.

Generally, the inter-grating pitch d of the diffraction grating and the diffraction wavelength λ are given by 2ndsin θ = mλ (m = 1, 2, 3 ...) When the incident angle is θ and the refractive index is n. Therefore, a layer having a high refractive index and a layer having a low refractive index are alternately laminated to form a diffraction grating, and at this time, by producing several types of layers having different inter-grating pitches d, it is possible to diffract light of various wavelengths. It is possible to widen the diffraction wavelength range of one diffraction grating.

Explaining a concrete example, when the average refractive index is 1.5, as shown in the sectional view of FIG. 1, for example, a high refractive index polymer layer 1 (n _d = 1.
59) with a low refractive index polymer layer 2 (n _d = 1.
41), 5 layers of 0.14 μm high refractive index polymer layer 3 (n _d = 1.59) and 5 layers of low refractive index polymer layer 4 (n _d = 1.41) having the same thickness are laminated. The thickness is sequentially increased, and the layers are repeatedly laminated in the same manner, and a high refractive index polymer layer 5 (n _d = 1.59) having a thickness of 0.67 μm and a low refractive index polymer layer 6 (n _d = 1.41) having the same thickness 5 are formed. The diffraction grating 10 is manufactured by stacking and stacking. The film thickness of this film 10 is 70 μm from the following calculation.

0.13 × 2 × 5 + 0.14 × 2 × 5 + ... + 0.67 × 2 × 5 = 70 μm This diffraction grating 10 allows the layer of the first thickness to be formed as shown in FIG. Set 1, 2 diffracts light with a wavelength of 800 nm, and sets of successively increasing thicknesses provide 840 nm,
・ ・ ・ Diffracts a wide range of light of 2000 nm. Here, the diffraction wavelength range and the diffraction efficiency can be arbitrarily set by changing the film thickness of the polymer layer, the number of laminated layers, and the refractive index difference.

Various coating methods such as roll coating, gravure coating, die coating, spray coating, blade coating and spin coating are conceivable as means for obtaining such a layer structure, and any coating method is applicable to the present invention. it can. Among these, a particularly preferable coating method is a spin coating method which can strictly control the film thickness even in the unit of 0.01 μm.

In the present invention, the polymer to be the polymer layer is preferably applied by spin coating as a polymer solution or an ionizing radiation curable material solution.

First, the case of coating as a polymer solution will be described below. When applying as a polymer solution, it becomes necessary to satisfy the following several conditions. The polymer is soluble in a solvent that can be dried by heating after spin coating. The refractive indices of the two polymers are different from each other. A solvent in which one polymer is dissolved does not dissolve the other polymer film. The combination of polymers satisfying these conditions can be determined by examining the refractive index, the solvent, and the non-solvent using a polymer handbook or the like.

Examples of the polymer which can be used in the production method of the present invention include polyvinylidene fluoride 1.42 polydimethylsilylene (polydimethylsiloxane) 1.43 polytrifluoroethyl methacrylate 1.437 polyoxypropylene 1.4495 polyvinyl isobutyl ether 1.4507 polyvinyl ethyl ether 1.4540 poly. Oxyethylene 1.4563 Polyvinyl butyl ether 1.4563 Polyvinyl pentyl ether 1.4581 Polyvinyl hexyl ether 1.4591 Poly (4-methyl-1-pentene) 1.459 -1.465 Cellulose acetate butyrate 1.46 -1.49 Poly (4-fluoro-2-trifluoromethylstyrene) 1.46 Polyvinyl octyl Ether 1.4613 Poly (vinyl 2-ethylhexyl ether) 1.4626 Polyvinyl decyl ether 1.4628 Poly (2-methoxyethyl acrylate) ) 1.463 Polybutyl acrylate 1.4631 Polybutyl acrylate 1.466 Poly (t-butyl methacrylate) 1.4638 Polyvinyl dodecyl ether 1.4640 Poly (3-ethoxypropyl acrylate) 1.465 Polyoxycarbonyltetramethylene 1.465 Polyvinyl propionate 1.4665 Polyvinyl acetate 1.4665 Polyvinyl methyl ether 1.467 Poly Ethyl acrylate 1.4685 Ethylene-vinyl acetate copolymer 1.47 -1.50 (80% -20% vinyl acetate) Cellulose propionate 1.47 -1.49 Cellulose acetate propionate 1.47 Benzyl cellulose 1.47 -1.58 Phenol-formaldehyde resin 1.47 -1.70 Cellulose triacetate 1.47 -1.48 Polyvinyl methyl ether (isotactic) 1.4700 Poly (3-methoxypropyl acrylate) 1.471 Poly (2-ethoxyethyl acrylate) 1.471 Polymethyl acrylate 1.472 -1.480 Polyisopropyl methacrylate 1.4728 Poly (1-decene) 1.4730 Polypropylene (atactic, density 0.8575 g / cm ³ ) 1.4735 Poly (vinyl sec-butyl ether) (isotactic) ) 1.4740 Polydodecyl methacrylate 1.4740 Polyoxyethylene oxysuccinoyl 1.4744 (Polyethylene succinate) Polytetradecyl methacrylate 1.4746 Ethylene-propylene copolymer (EPR-rubber) 1.4748-1.48 Polyhexadecyl methacrylate 1.4750 Polyvinyl formate 1.4757 Poly ( 2-Fluoroethylmethacrylate) 1.4768 Polyisobutylmethacrylate 1.477 Ethylcellulose 1.479 Polyvinyl acetal 1.48 -1.50 Cellulose acetate 1.48 -1.50 Cellulos Sodium propionate 1.48 -1.49 Polyoxymethylene 1.48 Polyvinyl butyral 1.48 -1.49 Poly (n-hexyl methacrylate) 1.4813 Poly (n-butyl methacrylate) 1.483 Polyethylidene dimethacrylate 1.4831 Poly (2-ethoxyethyl methacrylate) 1.4833 Polyoxyethylene Oxymale oil 1.4840 (Polyethylene maleate) Poly (n-propyl methacrylate) 1.484 Poly (3,3,5-trimethylcyclohexyl methacrylate) 1.485 Polyethyl methacrylate 1.485 Poly (2-nitro-2-methylpropyl methacrylate) 1.4868 Polytriethylcarb Vinyl methacrylate 1.4889 Poly (1,1-diethylpropyl methacrylate) 1.4889 Polymethyl methacrylate 1.4893 1.490 Poly (2-decyl-1,3-butadiene) 1.4899 Polyvinyl Alcohol 1.49 -1.53 Polyethyl glycolate methacrylate 1.4903 Poly (3-methylcyclohexyl methacrylate) 1.4947 Poly (cyclohexyl α-ethoxy acrylate) 1.4969 Methyl cellulose (low viscosity) 1.497 Poly (4-methylcyclohexyl methacrylate) 1.4975 Polydecamethylene glycol dimethacrylate 1.4990 Polyurethane 1.5 -1.6 Poly (1,2-butadiene) 1.5000 Polyvinyl formal 1.50 Poly (2-bromo-4-trifluoromethylstyrene) 1.5 Cellulose nitrate 1.50 -1.514 Poly (sec-butyl α-chloroacrylate) 1.500 Poly (2-heptyl-1,3-butadiene) 1.5000 poly (ethyl α-chloroacrylate) 1.502 poly (2-isopropyl-1,3 butadiene) 1.5028 poly (2-methylcyclohexyl meta) Relate) 1.5028 polypropylene (density 0.9075g / cm ³⁾ 1.5030 polyisobutene 1.505 -1.51 poly isobornyl methacrylate 1.5059 poly (2-t-butyl-1,3-butadiene) 1.5060 Polyethylene glycol dimethacrylate 1.5063 poly cyclohexyl methacrylate 1.5066 poly (cyclohexanediol -1,4-Dimethacrylate) 1.5067 Butyl rubber (unvulcanized) 1.508 Polytetrahydrofurfuryl methacrylate) 1.5096 Guttapercha (β) 1.509 Polyethylene ionomer 1.51 Polyoxyethylene (high molecular weight) 1.51 -1.54 Polyethylene (density 0.914 g / cm ³ ) 1.51 (density of 0.94-0.945g / cm ³⁾ 1.52 -1.53 (density 0.965 g / cm ³⁾ 1.545 poly (1-methylcyclohexyl methacrylate) 1.5111 poly (2-hydroxyethyl methacrylate) 1.5119 polyvinyl Luchloroacetate 1.512 Polybutene (isotactic) 1.5125 Polyvinyl methacrylate 1.5129 Poly (N-butyl-methacrylamide) 1.5135 Guttaperca (α) 1.514 Terpene resin 1.515 Poly (1,3-butadiene) 1.5154 Shellac 1.51 -1.53 Poly (methyl α-) Chloroacrylate) 1.517 Poly (2-chloroethylmethacrylate) 1.517 Poly (2-diethylaminoethylmethacrylate) 1.5174 Poly (2-chlorocyclohexylmethacrylate) 1.5179 Poly (1,3-butadiene) (35% cis; 56% trans 1.5180; 7 % 1,2-contet) Natural rubber 1.519 -1.52 Polyallyl methacrylate 1.5196 Polyvinyl chloride + 40% Dioctyl phthalate 1.52 Polyacrylonitrile 1.52 1.5187 Polymethacrylonitrile 1.52 Poly (1,3-butane) En) (sic type rich) 1.52 butadiene-acrylonitrile copolymer 1.52 polymethylisopropenyl ketone 1.5200 polyisoprene 1.521 polyester resin rigid (about 50% styrene) 1.523 -1.54 poly (N- (2-methoxyethyl) methacrylamide) 1.5246 Poly (2,3-dimethylbutadiene) (methyl rubber) 1.525 Vinyl chloride-vinyl acetate copolymer (95 / 5-90 / 10) 1.525 -1.535 Polyacyl acid 1.527 Poly (1,3-dichloropropyl methacrylate) 1.5270 Poly ( 2-chloro-1- (chloromethyl) ethylmethacrylate) 1.5270 polyacrolein 1.529 poly (1-vinyl-2-pyrrolidone) 1.53 chlorinated rubber 1.53-1.55 nylon 6; nylon 6,6; nylon 6,10 (molded body) 1.53 (nylon-6-fiber: 1.515 transverse direction 1.565 fiber Fiber direction) Butadiene-styrene copolymer (about 30% styrene) 1.53 Block copolymer Poly (cyclohexyl α-chloroacrylate) 1.532 Poly (2-chloroethyl α-chloroacrylate) 1.533 Butadiene-styrene copolymer (about 75 / 25) 1.535 Poly (2-aminoethyl methacrylate) 1.537 Polyfurfuryl methacrylate 1.5381 Protein 1.539 -1.541 Polybutyl mercaptyl methacrylate 1.5390 Poly (1-phenyl-n-amyl methacrylate) 1.5396 Poly (N-methyl-methacrylamide) 1.5398 Cellulose 1.54 Polyvinyl chloride 1.54-1.55 Ureaformaldehyde resin 1.54-1.56 Poly (sec-butyl α-bromoacrylate) 1.542 Poly (cyclohexyl α-bromoacrylate) 1.542 Poly (2-bromoethylmethacrylate) ) 1.5426 Polydihydroabietic acid 1.544 Polyabietic acid 1.546 Polyethyl mercaptyl methacrylate 1.547 Poly (N-allyl methacrylamide) 1.5476 Poly (1-phenylethyl methacrylate) 1.5487 Polyvinylfuran 1.55 Poly (2-vinyltetrahydrofuran) 1.55 Poly ( Vinyl chloride) + 40% tricresyl phosphate 1.55 Epoxy resin 1.55 -1.60 Poly (p-methoxybenzyl methacrylate) 1.552 Polyisopropyl methacrylate 1.552 Poly (p-isopropylstyrene) 1.554 Polychloroprene 1.554 -1.558 Poly (oxyethylene-α-benzoate -Ω-methacrylate) 1.555 poly (p, p'-xylylenyl dimethacrylate) 1.5559 poly (1-phenylallyl methacrylate) 1.5573 poly (p-cyclohexylphene) Nyl methacrylate) 1.5575 Poly (2-phenylethyl methacrylate) 1.5592 Poly (oxycarbonyloxy-1,4-phenylene-1-propyl 1.5602-butylidene-1,4-phenylene) poly (1- (o-chlorophenyl) ethyl methacrylate ) 1.5624 Styrene-maleic anhydride copolymer 1.564 Poly (1-phenylcyclohexyl methacrylate) 1.5645 Poly (oxycarbonyloxy-1,4-phenylene-1,3 1.5671-dimethyl-butylidene-1,4-phenylene) poly ( Methyl α-bromo acrylate) 1.5672 Polybenzyl methacrylate 1.5680 Poly (2- (phenylsulfonyl) ethyl methacrylate) 1.5682 Poly (m-cresyl methacrylate) 1.5683 Styrene-acrylonitrile copolymer (about 75/25) 1.57 Poly (oxycal) Bonyloxy-1,4-phenylene isobutylidene 1.5702-1,4-phenylene) poly (o-methoxyphenylmethacrylate) 1.5705 polyphenylmethacrylate 1.5706 poly (o-cresylmethacrylate) 1.5707 polydiallylphthalate 1.572 poly (2,3-) Dibromopropyl methacrylate) 1.5739 Poly (oxycarbonyloxy-1,4-phenylene-1-methyl 1.5745-Butylidene-1,4-phenylene) Poly (oxy-2,6-dimethylphenylene) 1.575 Polyoxyethylene oxyterephthaloyl (Amorphous) 1.5750 (Polyethylene terephthalate) (Crystalline fiber: 1.51 Transverse direction 1.64 Fiber direction) Polyvinyl benzoate 1.5775 Poly (oxycarbonyloxy-1,4-phenylene butylidene 1.5792-1,4-phenylene) Poly ( 1,2-diphenylethylmethacrylate) 1.5816 poly (o-chlorobenzylmethacrylate) 1.5823 poly (oxycarbonyloxy-1,4-phenylene-sec-1.5827 butylidene-1,4-phenylene) polyoxypentaerythritoloxyphthaloyl ) 1.584 Poly (m-nitrobenzyl methacrylate) 1.5845 Poly (oxycarbonyloxy-1,4-phenylene isopropylidene 1.5850-1,4-phenylene) Poly (N- (2-phenylethyl) methacrylamide) 1.5857 Poly (4 -Methoxy-2-methylstyrene) 1.5868 Poly (o-methylstyrene) 1.5874 Polystyrene 1.59 -1.592 Poly (oxycarbonyloxy-1,4-phenylenecyclohexylidene 1.5900-1,4-phenylene) Poly (o-methoxystyrene) ) 1.5932 polydiphenylmethyl Methacrylate 1.5933 Poly (oxycarbonyloxy-1,4-phenylene ethylidene 1.5937-1,4-phenylene) Poly (p-bromophenyl methacrylate) 1.5964 Poly (N-benzylmethacrylamide) 1.5965 Poly (p-methoxystyrene) 1.5967 Curing Rubber (32% S) 1.6 Polyvinylidene chloride 1.60 -1.63 Polysulfide ("Thiokol") 1.6 -1.7 Poly (o-chlorodiphenylmethylmethacrylate) 1.6040 Poly (oxycarbonyloxy-1,4- (2,6-dichloro) 1.6056 phenylene-isopropylidene-1,4- (2,6-dichloro) phenylene) poly (oxycarbonyloxybis (1,4- (3,5-1.6056 dichlorophenylene))) polypentachlorophenyl methacrylate 1.608 poly (o -Chlorostyrene) 1.6098 poly Phenyl α-bromoacrylate) 1.612 Poly (p-divinylbenzene) 1.6150 Poly (N-vinylphthalimide) 1.6200 Poly (2,6-dichlorostyrene) 1.6248 Poly (β-naphthylmethacrylate) 1.6298 Poly (α-naphthylcarbylmethacrylate) 1.63 Polysulfone 1.633 Poly (2-vinylthiophene) 1.6376 Poly (α-naphthylmethacrylate) 1.6410 Poly (oxycarbonyloxy-1,4-phenylenediphenyl) 1.6539-Methylene-1,4-phenylene) Polyvinylphenyl sulfide 1.6568 Butylphenolformaldehyde resin 1.66 Urea-thiourea-formaldehyde resin 1.660 Polyvinylnaphthalene 1.6818 Polyvinylcarbazole 1.683 Naphthalene-formaldehyde resin 1.696 Phenol-formaldehyde resin 1.70 Poly Printer-bromophenyl methacrylate 1.71, and the like. The refractive index (n _d ) of the d-line is also shown above.

Further, as a typical solvent, methanol,
Examples include organic solvents having relatively low boiling points such as ethanol, n-propanol, isopropanol, amyl alcohol, acetone, methyl ethyl ketone, methyl isobutyl ketone, ethylene chloride, chloroform, benzene, toluene, xylene, hexane, heptane, and cyclohexane, and water. .

The case of applying as an ionizing radiation curable material solution is as follows. As the ionizing radiation curable material, an electron beam curable resin and an ultraviolet curable resin are useful, and the electron beam curable resin and the ultraviolet curable resin are that the latter contains a photopolymerization initiator and a sensitizer. Except for, the composition is similar, generally, as a film-forming component, a polymer having a radically polymerizable active group in its structure, an oligomer, a monomer as a main component, in terms of viscosity, It is preferably 2000 cps or less. As such polymers and oligomers, those easily available from commercial products such as urethane acrylate and polyester acrylate are applicable to the present invention. As the monomer, an ionizing radiation curable monomer such as a commercially available acrylic acid or methacrylic acid derivative can be applied to the present invention. In order to make the curable resin an ultraviolet curable resin, as a photopolymerization initiator therein, acetophenones, benzophenone, Michler benzoyl benzoate, α-aminoxime ester, tetramethyl thiuram monosulfide, thioxanthones, or As a photosensitizer, n-butylamine, triethylamine, tri-n
-Butylphosphine etc. can be mixed and used.

In this case, the above material is applied to a predetermined thickness by spin coating and then irradiated with ionizing radiation to form a polymer layer. As the ionizing radiation irradiation method, the conventional technique can be applied as it is. For example, in the case of electron beam irradiation, Cockloft-Walton type, Van de Graaff type, resonance transformation type, insulating core transformer type, linear type, dynamitron type, high frequency type 50-1,000 KeV, preferably 100-30, emitted from various electron beam accelerators such as
An electron beam having an energy of 0 KeV is emitted from 0.1 to 10
0 Mrad. , Preferably 1-10 Mrad. It can be cured by irradiation, and in the case of ultraviolet irradiation, ultra high pressure mercury lamp, high pressure mercury lamp, carbon arc,
Ultraviolet rays emitted from a light source such as a xenon arc or metal halide lamp is 0.1 to 10,000 mJ / c.
It can be cured by irradiation with m ² , preferably 10 to 1,000 mJ / cm ² .

In general, in the spin coating method, the coating film thickness h is given by h = Kμ ^0.36 ω ^-0.50 (Eλ / C _p ) ^0.60 . Here, K: constant, μ: coating agent viscosity,
ω: angular velocity of spinner, E: relative evaporation rate, λ: latent heat of vaporization, C _p : heat capacity.

Therefore, the conditions for applying the polymer film to a predetermined thickness are determined by previously applying the polymer solution at a predetermined viscosity and a predetermined number of revolutions to obtain the relationship between the film thickness and the number of revolutions. be able to.

As is clear from the above description, according to the method of manufacturing a diffraction grating of the present invention, a layer formed of two or more kinds of polymers having different refractive indexes has a high refractive index and a high refractive index is repeated. It is a manufacturing method characterized by producing by laminating a refractive index polymer layer and a low refractive index polymer layer in order by a coating method.

In this case, it is necessary to make the thicknesses of the polymer layers different in at least some of the layers in order to perform diffraction in a wide wavelength range.

Further, the polymer layer is prepared by coating a polymer solution dissolved in a solvent which can be dried by heating and does not dissolve the adjacent polymer layer, or
It is prepared by coating an ionizing radiation-curable liquid capable of forming a polymer film by irradiation with ionizing radiation.

When it is difficult to apply the polymer solution uniformly due to repellency or the like, it can be solved by surface treatment such as corona treatment and ozone treatment.

It is desirable to use spin coating as the coating method.

[0023]

In the present invention, a high refractive index polymer layer and a low refractive index polymer layer are sequentially coated so that a layer composed of two or more kinds of polymers having different refractive indexes is repeated with relatively high and low refractive indexes. Since the layers are manufactured by laminating, the diffraction grating having a wide diffraction wavelength can be easily manufactured by laminating the layers with different thicknesses.

[0024]

EXAMPLES Examples of the method for manufacturing a diffraction grating of the present invention will be described below. Example 1 Polystyrene (PSt, n _d
= 1.592) as a low refractive index polymer layer and polyhydroxyethyl methacrylate (PHEMA, n _d = 1.
46) is used to diffract light having a wavelength of 800 nm to 2000 nm, with a thickness of 0.033 pitch between 0.129 μm and 0.327 μm, and 20 sets of high refractive index for each thickness. A multi-layer polymer layer consisting of lower layers was prepared.

Here, PSt is a commercially available product having a molecular weight of 100,000 (manufactured by Denka Corporation) in a 5% dioxane solution (viscosity: 10.
0 cps), PHEMA was prepared by applying a synthetic product having a molecular weight of 100,000 as a 7% methanol solution (viscosity: 12.3 cps). PHEMA was synthesized by radical polymerization with a monomer concentration of 30% in methanol and 0.1% of an initiator (V-65: manufactured by Wako Pure Chemical Industries, Ltd.).

The following table shows the spin coating conditions of PSt and PHEMA for each film thickness.

[0027] The diffraction efficiency of the obtained diffraction grating was measured by a spectrophotometer (UV-3
65: manufactured by Shimadzu Corporation), 800 nm
It was found that the average diffraction efficiency was 48% in the range of up to 2000 nm.

Example 2 As the high refractive index polymer layer and the low refractive index polymer layer, the following ionizing radiation curable compositions were used.

High Refractive Index Polymer Layer Urethane Acrylate (PR-202: Mitsubishi Kasei Co., Ltd.) 50 parts by weight 2,4,5-Tribromophenol methacrylate 150 parts by weight (Wako Pure Chemical Industries, Ltd.) Dipentaerythritol pentaacrylate: 5 parts by weight (Sartomer 399: manufactured by Sartomer) Viscosity: 10 cps, refractive index: 1.58 Low refractive index polymer layer Urethane acrylate (PR-202: manufactured by Mitsubishi Kasei) ... 50 Parts by weight 2,2,3,3-tetrafluoropropyl acrylate ... 150 parts by weight (manufactured by Daikin Chemicals Co., Ltd.) Dipentaerythritol pentaacrylate ... 5 parts by weight (Sartomer 399: manufactured by Sartomer) , Refractive index: 1.47 Spin coat of high and low refractive index materials for each film thickness Shows the conditions in the table below.

[0030] After spin coating, each layer was exposed to an electron beam of 5 Mrad.
Irradiation (manufactured by ESI Co., Ltd.) was carried out to cure and form a polymer layer. For each film thickness, 10 pairs of high refractive index layers and 10 low refractive index layers were alternately laminated to form a diffraction grating.

The diffraction efficiency of the obtained diffraction grating was measured with a spectrophotometer (UV-365: manufactured by Shimadzu Corporation), and it was found that the diffraction efficiency was 52% on average in the range of 800 nm to 2000 nm. .

[0032]

As is apparent from the above description, according to the method of manufacturing a diffraction grating of the present invention, a layer made of two or more kinds of polymers having different refractive indexes is repeated with relatively high and low refractive indexes. In addition, since a high refractive index polymer layer and a low refractive index polymer layer are laminated by a coating method in order,
By stacking layers with different thicknesses, it is possible to easily manufacture a diffraction grating having a wide diffraction wavelength.

Specifically, the diffraction wavelength range is set to 800, for example.
The thickness can be set to nm to 2000 nm, and in this case, a good heat ray reflective film that transmits visible light and reflects heat rays is obtained.
By using this heat ray reflective film for a window of an automobile or a building, it is possible to reduce an increase in temperature inside the vehicle and in the room.

As a use other than such a heat ray reflective film, the present invention can be applied to a color filter for a liquid crystal display or the like which reflects light of a specific wavelength in the visible region, an ultraviolet cut film and the like.

[Brief description of drawings]

FIG. 1 is a laminated sectional view of one specific example of a diffraction grating manufactured by a manufacturing method of the present invention.

FIG. 2 is a diagram showing diffraction characteristics of the diffraction grating of FIG.

[Explanation of symbols]

1 ... High refractive index polymer layer (n _d = 0.13 μm)
1.59) 2 ... Low refractive index polymer layer (n _d = 0.13 μm)
1.41) 3 ... High refractive index polymer layer (n _d = 0.14 μm)
1.59) 4 ... Low refractive index polymer layer (n _d = 0.14 μm)
1.41) 5 ... High refractive index polymer layer (n _d = 0.67 μm)
1.59) 6 ... low-refractive index polymer layers having a thickness of 0.67 .mu.m (n _d =
1.41) 10 ... Diffraction grating (film thickness 70 μm)

Claims (5)

[Claims] 1. A high-refractive-index polymer layer and a low-refractive-index polymer layer are sequentially laminated by a coating method so that a layer composed of two or more kinds of polymers having different refractive indexes is repeated with relatively high and low refractive indexes. A method of manufacturing a diffraction grating, which comprises: 2. The method for producing a diffraction grating according to claim 1, wherein the polymer layers are made to have different thicknesses among at least some of the layers to enable diffraction in a wide wavelength range. 3. The production of a diffraction grating according to claim 1, wherein the polymer layer is produced by coating a polymer solution dissolved in a solvent which can be dried by heating and does not dissolve the adjacent polymer layer. Method. 4. The method for producing a diffraction grating according to claim 1, wherein the polymer layer is produced by coating an ionizing radiation curable liquid capable of forming a polymer film by irradiation with ionizing radiation. 5. The coating method according to claim 1, wherein spin coating is used.
A method of manufacturing a diffraction grating according to the item.